Punch press



June 4 D. c. VERSON Em 2,286 9 3 PUNCH PRESS Filed Oct. 14, 1940 3Sheets-Sheet 1 June 16, 1942. o. c. VERSON ET AL PUNCH PRESS Filed Oct.14, 1940 3 Sheets-Sheet 2 n l n m U u Patented June 16, 1942 UNITEDSTATES PTQNT OFFICE PUNCH PRESS ware Application October 14, 1949,Serial No. 361,040 9 Claims. (Cl. 192 -144) This invention relates topunch presses, and more particularly to a mechanical punch press havinga stroke of variable length.

The term punch press is used in its generic sense in this applicationand is meant to include press brakes, extruding presses and similarmetal deforming machines.

In the past, the principal disadvantage of mechanical presses, ascompared with hydraulic presses, was that although a mechanical presscould be constructed to have a long stroke and might, therefore, beadmirably suited for some particular manufacturing processes, yet such apress was not readily adaptable for use in drawing operations wherein ashorter stroke was adequate. The principal disadvantage inherent in apress having an invariable stroke is that such a press having a longstroke of, say, thirty inches, for instance, must necessarily have acomparatively slow cycle of operation, since the crank or eccentric mustbe started from its uppermost position, moved downwardly through itslowermost position and back upwardly to its uppermost position again. Ifthe effective stroke desired from such a press is short, for instanceonly four inches, it will still be necessaryto move the slide from itsuppermost position downwardly to within four inches of the bottom of itsstroke before doing any work on the metal to be deformed. Likewise, theentire upward stroke from the lowermost position of the crank to itsuppermost position is similarly wasted since no work is done.

Therefore, the principal object of our invention is to provide a punchpress wherein the length of stroke may be predetermined and preset froma minimum of nothing to a maximum of the full stroke for which themachine is intended.

An additional object is the provision of such a press wherein the lengthof stroke may be preset without the necessity for complicatedadjustments to the crank mechanism itself.

Still a further object of our invention is the provision of a mechanicalpunch press wherein the adjustment of the stroke is such a simpleoperation that it is feasible to use successive strokes of differentlengths in a manufacturing process, if desired.

An additional object of our invention is the provision of a punch presshaving a stroke of variable length wherein the time of the cycle ofoperation of the press is progressively shorter as the stroke isshortened.

Other objects and advantages will become apparent from the followingdescription of a preferred embodiment of our invention, taken inconjunction with the accompanying drawings in which similar charactersof reference refer to similar parts throughout the several views:

Fig. l is a somewhat diagrammatic front view of a press embodying thepresent invention;

Fig. 2 is a left side view of the press illustrated in Fig. l, and vFig. 3 is a somewhat diagrammatic sectional view, taken in the directionindicated by the arrows along the line 3-3 of Fig. 1, showing theconstruction and arrangement of parts in the press crown. The controlmechanism is also diagrammatically shown in this view.

In punch presses as ordinarily constructed, a heavy flywheel is rotatedat a substantially constant speed by a prime mover. When the operatorpresses the proper control, an electrical, mechanical or pneumaticmeans, or a combination of these control means, engages a clutch whichconnects the crank shaft to the fly wheel, while simultaneously a brakewhich prevents the crank shaft from moving is released. Thus, the flywheel is connected to the crank and the energy stored in the fly wheelrotates the crank from its uppermost position downwardly through itslowermost position and upwardly toward its uppermost position onceagain. As the crank reaches this uppermost position, automatic mechanismcomes into play to disengage the clutch between the fly wheel and thecrank, while simultaneously the brake is applied. Thus, the crank shaftis stopped at this uppermost position in preparation for a second cycle.

It will be seen that this construction necessitates that the crank shaftalways rotate through a complete revolution in order to complete a cycleof operation and that, therefore, the slide connected by a pitman to thecrank shaft always passes through a full stroke.

In the press of our invention we also use a fly wheel which is driven ata constant speed by a prime mover. We connect this fly wheel alternatelyby means of a pair of clutches to two separate gear trains connectedbetween the clutches and the crank. One of these gear trains contains anidler gear not found in the other gear train in order to reverse thedirection of rotation of the crank shaft relative to the fly wheel.Thus, by

engaging one clutch, we are able to swing the crank pin in onedirection, while by engaging the other clutch, the crank shaft may berotated in the opposite direction. 7

In connection with this arrangement we also provide a control mechanismwhich disengages which ever clutch has been previously engaged andsimultaneously applies the brake before the crank pin is returned to itsuppermost position. Thus, for instance, starting with the crank pinpositioned at a point in its cycle a matter of or so from its lowermostposition,- a control is prearranged by the operator to determine thelength of stroke desired.- The punch press operating control is thenactuated, thereby causing the control mechanism to release the brake andengage the appropriate clutch. The fly wheel-V then swings the crankthrough its lowermost position and upwardly once more to the pointpredetermined by the operaton At this point in its cycle the automaticcontrolmechanism will cause the clu'tch'to become-dis-- engaged and thebrake to be applied, thus stopping the press. When the operator nextoperates. the press starting control, the mechanism will cause the otherof the two clutches to-be en gaged simultaneously with the release ofthe be seen that only half as many revolutions of the fly wheel will berequired to rotate the'crank a half revolution as would be requiredto'rotate the crank a full revolution.

In the embodiment of our inventioniillustrated in the drawings we haveshown apunch press having-a stroke variable from zero to a maximum ofapproximately thirty inches. This press, indicatedgenerally by thenumeral I0, is comprised of a frame I2 and a slide l4. At the lowerportion of the frame, a bed It supports a lower die element It, whilethe lower surface of the slide it carries the cooperating die element20. At the upper portion of the frame, the press is provided With acrown 22 which carries a cross shaft. 23. At its center this shaftjournals an eccentric 25 which-is connected by means of an eccentricstrap 28 to the press slide 14. Thus, rotation of the eccentric 26causes the. eccentric strap 23 to reciprocate the slide M toward andaway from the bed I8. The eccentric 28 is secured at each side to alarge gear 38, these gears being meshed with smaller pinions 32 carriedupon a cross. shaft 34' journal'ed' at its ends at in the press crown.

Referring particularly to Fig.3, it will be seen that the left-hand endof the shaft 34 is keyed to a large gear 33 meshed with a pinion 40. Thepinion is in turned mounted upona short shaft tip-ositioned parallel tothe shaft 34' and journaled at its ends inthe press crown. A large gear5 1 carried upon this shaft 42 is meshed with apinion 46 mounted upon aprimary drive shaft 48.

Similarly, the rig-ht hand end of the shaft 34 is provided with a gear58 meshed with a pinion carried by a short shaft 54. This short shaft 54also carries a large gear 55 meshed with an idling or reversing gear 58which, in turn, is meshed with a pinion 60 keyed to a second primarydrive shaft 62.

The ratios of the two gear trains between the ends of the primary driveshafts 48 and 62 and the shaft 34 are the same, excepting that theidling or reversing gear 58 found in the righthand train is not presentat the left-hand side of the press, thus causing the two primary driveshafts ta-and 62 to rotate at the samespeed, but in opposite directions.

The two primary drive shafts 48 and 62 are in axial alignment with theirouter ends journaled in suitable bearing members in the press crown.The: inner ends of these shafts are closely adjacent eachother and arejournaled to rotate relative to-awheel 64. This fly wheel 64 is-'carried in bearing-members 68 in the press crown,

tween the bell and disc.

Within-the bell"'l'2,' a collar- 18 keyed to the shaft 62, is providedwith an'outwardly radiating annular clutch driven plate 18 5which ispositioned closely adjacent the face of the driving disc 14. A similarannular clutchdriven plate is positioned on the opposite or outward sideof the driving disc 14-and is free to move longitudinally relative tothe clutch plate '-l8onsplines 19-, but is prevented'from rotatingrelative to this plate.

A piston 82 operating in a' cylinder 84 secured to the shaft 62, acts tourge the driven plate 85- toward the driven plate 18 when the cylinder34 is placed under pneumatic pressure. This cylinder receives-air underpressure through a port 8B whichcommunicates withalongitudinallyextending passage 88in the shaft 62. Air is fed toorexhausted' from thispassage 83 through anair line SD and cap92. Thecap92 fits-overthe'outer end of" the shaft 52 and is sealed to'the shaftbya cup washer 93 or other suitable rotary sealE Thus; byadmitting airunder pressuretothe airline-', air is caused to flow through the'cap-9'2 passage 88; and thence through the port 86into the cylinder 84. Theresulting increase inpressure in the cylinder 84 moves the piston 82toward the fly wheel; thus pushing the clutch plate 88 against the-discT4. Continued movement of this piston urges the clutch disc M -againstthe inner clutch plate 18 sothat the clutch disc 14- istightly clampedbetween the two driven-plates wand 88, thus causing the shaft 62 -t'orevolve with the fly wheel 64.

A- plurality of coil springs 94 bear with one of their ends-against theouter face of the cylinder 84 and with their other ends against heads 96of clutch release pins 98- which extend through openings in the cylinder84 and are connected at their inner ends to the piston 82. These springsurge the piston toward the right, thus disengaging the clutchwhen air ispermitted to flow fromthe cylinder 84.-

A similar clutch I08 is arranged at the lefthand side of the fly wheel84 and similarly connects the flywheel to theshaft 48 when engaged. Thisclutch is actuated by a piston- H32 acting in a pneumatic cylinder [Minthe same manner as piston 82 actuates the previously mentioned clutch H,

Directly to the left of the clutch cylinder I24 the shaft 48 is providedwitha collar- I06, the

external face of which is splined at I08. A bell IIII, secured to thecrown at the left-hand side of the machine, extendsinwardly andsurrounds the shaft and at approximately the mid point of the collar I06is provided with an annular brake disk H2. The connection between thebrake disc H2 and the bell II is splined at II4 to permit a limitedlongitudinal movement of the brake disc, but prevents relative rotationbetween these elements.

An annular brake plate I I6 is slidable on the splines at I08 and issecured to the outer ends of clutch release pins H8. These pins extendthrough the cylinder I04 and are secured at their opposite ends to thepiston I02, while the portions of the pins between the cylinder I04 andthe brake plate II6 pass through coil springs i530. Thus, these springsI20 act in the same manner as the spring 94 to release the clutch whenair is exhausted from the space within the cylinder I04. In addition, itwill be seen that since their outer ends are connected to the brakeplate II 6, the springs will urge this brake plate against the brakedisc II2 simultaneously with the disengagement of the clutch I00.

At the opposite side of the brake disc II2 the splined collar I06 isprovided with a similar slidable brake plate I22 which is connected bybrake release pins I 24 to a brake release piston I26 slidable in acylinder I28. The cylinder I28 is secured to the shaft 48 in the samemanner as the cylinder I04. Thus, movement of the piston I26 toward theleft pulls the brake release pins I24 toward the left, thus pulling thebrake plate I22 away from the disc I I2. Coil springs I30 surround thepins I24 and bear with their opposite ends against the plate I22 and therelease cylinder I28, so that the brake plate I22 is normally pushedtoward the right by these springs. The two cylinders I04 and I28 areconnected by concentric passages I32 and I34 in the shaft 48 to airlines I36 and 90, respectively, through the medium of a cap I38 having apair of rotary seals I40 and I42 so that air may be admitted to orexhausted from either the cylinder I04 or the cylinders 84 and I 28together.

When at rest, all of the cylinders will be at substantially atmosphericpressure. Thus, both of the clutches will be disengaged while thesprings I20 and I30 act to urge the brake plates H6 and I22 fromopposite directions against the brake disc II2, thereby preventingrotation of the shaft. Simultaneously with the engagement of the clutchI00, the brake plate H6 will be drawn toward the right and the brakereleased. If, on the other hand, cylinder 84 is placed under pressure toengage clutch II, the arrangement of the air lines is such that brakerelease cylinder 28 is simultaneously placed under pressure to move thebrake plate I22 to the left and release brake disc II2, therebypermitting free rotation of the driving mechanism. It will be seen,therefore, that by alternately engaging and disengaging clutches I00 andH, the eccentric 26 is alternately driven through the gear trains atalternate sides of the press, while all of the braking is done throughthe gear train at the left-hand side of the press, as Viewed in Fig. 3.

The control mechanism shown diagrammatically in the drawings is merelyan example of one type of control by means of which the press may beoperated in the manner we have described.

Referring to the lower portion of Fig. 3, we

have shown a manually and automatically operable rotary valve I44 which,when revolved in a counter-clockwise direction, assumes the positionshown. In this position air passes from an air receiver, not shown,through the conduit I46 and by way of a passage I48 in the air valve toa conduit I50, thus putting the conduit I 50 under pneumatic pressure.When the valve I44 is rotated in a clockwise direction, air passes fromthe con duit I50 by way of a branch passage I52 in the air valve,through the air valve passage I48 and thence to an exhaust line I54.Thus, with the valve I44 rotated to its clockwise position, the air inconduit I50 is exhausted to the atmosphere, thus placing this conduit atsubstantially atmospheric pressure.

The conduit I 50 leads to a rotary selector valve I56 which serves todistribute the air to either one or the other of the press clutches.Thus, with the valve I56 rotated to its counterclockwise position asshown, air under pressure passes from the conduit I50 through a passageI58 in the valve I56 and through air line I36 leading to cylinder I04.Simultaneously the air line is connected by means of a passage I60 inthe air valve to an exhaust line I62, thus placing cylinders I28 and 84at substantially atmospheric pressure. With the valve rotated to itscounterclockwise position, air line 90 will be connected to the conduitI50 through the medium of a passage I64 in the valve I56, while air lineI36 will be connected to the exhaust line I62 by means of a valvepassage I66.

With this arrangement the operator will, for instance, swing anappropriate lever which moves valve I56 to the position shown. Thenvalve I44, which previously had been in its clockwise position, is swungin a counter-clockwise direction to the position shown. Air then passesfrom the air receiver, not shown, through the air line I46, passage I48,conduit I50, passage I 58, and air line I36 to the cylinder I04. Thismoves piston I02 to the right and engages clutch I00 while simultaneously releasing the brake. The fly wheel then swings the eccentricthrough the medium of the gearing at the left-hand side of the pressthrough the portion of the cycle desired, whereupon air valve I44 isswung to its clockwise position, thus permitting the air in cylinder I04to escape through air line I36, passage I58, conduit 1'50, air valvepassages I52 and I48 to the exhaust line I52. This permits the springsI20 to disengage the clutch and apply the brake, thus stopping thepress.

Before the next stroke of the press, the selector control lever is movedto rotate valve I56 to its clockwise position so that when valve I44 isagain rotated to its counter-clockwise position as shown, air will passfrom the air line I 46 through passage I58, conduit I50, valve passageI64 and air line 30 to cylinders 84 and I28, thus engaging clutch II andmoving brake plate I 22 to the left to release the brake. The eccentricis then driven through the gearing at the righthand side of the press,thus swinging the eccentric in the opposite direction through itslowermost point and upwardly to the proper position, whereupon air valveI44 is again swung in a clockwise direction to permit air to beexhausted from the cylinders 84 and I28 to stop the press. During theabove cycle cylinder I04 is connected to the atmosphere through air lineI36. valve passage I66 and exhaust line I62.

Referring to Fig. 1, an automatic and simple arrangement is shown forstopping the press at the desired point in its cycle. This arrangementconsists of a vertical bar no which extends along the press column andis adapted to reciprocate in guides Ill. The lower end of this bar ispivotally connected to the valve I44 at IHl so that movement of this barin an upward direction swings the valve Hi l in a counterclockwisedirection, while downward movement of this rod swings the valve IM in aclockwise direction,

This rod I78 is automatically moved downwardly to shift the valve I44 toits clockwise position by means of a generally horizontal lever I15pivoted to the bar I'II'I and to a pin I18, fixed in the press frame andspaced somewhat inwardly from the bar I'll), The end of the lever I76opposite to that pivoted'to the bar I'IEI is provided with a leaf springI82 which extends transversely in front of thepress slide M. Behind theleaf spring I82 the press slide is provided, with a vertically extendingrail let to which av movable stop member I85 may be clamped at anypoint. As the slide moves upwardly, the stop member I875 carriedtherewith impinges against, the leaf spring I82 and moves the leafspring upwardly, thus shifting the rod Iii! downwardly and rotating thevalve M4 to its clockwise position and, by the arrangement previouslydescribed, stops the press. With. the

press slide in this position against the spring nember I82, the. valveismaintained, resiliently in. this position.

To start the next cycle of operation after shifting the selector valveI56, the operator shifts the valve I44 to its counter-clockwise position3 against the pressure of thespring I32 and holds it there momentarilyuntil the slidehas moved downwardly sufficientl to carry the stop memberI85 away from the spring I 22. The operator then removes his hand fromthe control lever of valve IM so that when. the slide moves upwardlyagain, the. stopping member I86 will be able once more to shift the. rodIlil downwardly to stop the press. The member I35 may be clamped. at anypointalong the rail I35 so i that the press slide may be permittedtomove upwardly to the desired point before it automatically disengagesthe clutch and applies the .brake. l

Having thus described our. invention, what we desire to secureby. UnitedStates Letters Patent is;

1. In a, variable strolge mechanicalpunch press of the type having apress frame, a slidereciprocable in the frame, rotatable means toreciprocate said slide, a. fly wheel, and means to To.- tate said flywheel, in one direction: meansincluding a clutch operable selectively todrive said rotatable means in one direction from said fly wheel, meansincluding another clutch selectively operable to drive said rotatablemeans fromsaid fly wheel in another direction, a brake to preventrotation of said rotatable means, and means to release said brakesubstantially simultaneously with the engagement of either of saidclutches and to apply said brake whenever both of said clutches aredisengaged.

2. In a device of the class described havingv a press frame, a slidereciprocable in said frame, rotatable eccentric means to reciprocatesaid slide, and a fly wheel: a pair of gear trains selectively operableto rotate said rotatableeccentric means from said fly wheel, meansselectively to drive. said rotatable eccentric means through alternateof said gear trains, means automatically to stop the rotation of saidrotatable means at any selected position of said slide during upwardmovement' of said slide, said means including a brake, and automaticmeans to disestablish driving relationship between said fly wheel andsaid rotatable eccentric means and substantially simultaneously to applysaid brake.

3. In a punch press of the type having a frame, a slide reciprocable insaid frame, rotatable eccentric means to reciprocate said slide, and arotatable fly wheel: selectively engageable clutch means operableselectively to drive said rotatable eccentric means from said fly wheelin either direction, brake means toprevent rotation of said rotatableeccentric means, pneumatic means selectively to operate said clutchmeans and to operate said brake means, and means to control the flow ofair to and from said pneumatic means, whereby said rotatable eccentricmeans may be revolved through less than a complete revolutionand wherebysaid rotatable eccentric means may be rotated alternately in oppositedirections.

4. In a mechanical punch press having a frame, a slide reciprocable inthe frame, eccentric means connected to said slide and adapted whenrotated through one complete cycle of revolution to cause said slide tomove from its uppermost position to its lowermost position and to returnto its uppermost position, a flywheel and means to rotate said flywheelat a substantially uniform velocity: clutch means adapted selectively toconnect said flywheel to said eccentric means to cause said flywheel torotate said eccentric means in one direction or alternatively to causesaid eccentric means to be rotated in the opposite direction, brakemeans adapted when applied to stop rotation of said eccentric means,means to apply said brake means when said clutch means is disengaged andto, release said brake means when said clutch means is engaged, andpre-set automatic means operative after the start of a cycle broughtabout by engagement of said clutch means and release of said brake meansto disengage said clutch means and to apply said brake means after saideccentric means has moved through a portion of a cycle includingmovement through its lowermost position but before said eccentric meanshas. moved through a complete cycle.

5. In a mechanical punch presshaving a frame, a slide reciprocable inthe frame, eccentric means connected to said slide and adapted whenrotated through one complete cycle of revolution to cause said slide to.move from its uppermost position to its lowermost position and. toreturn to its uppermost position, the distance between said uppermostand lowermost positions constituting the maximum length of stroke ofsaid press, a flywheel and means to rotate said fly- Wheel at asubstantially uniform velocity: connecting means between said flywheeland said eccentric means by means of which said eccentric means can be,rotated in either direction from said flywheel, adjustable control meansto stop the rotation of said eccentric means during the upstroke of saidslide when said slide is at any predetermined intermediate positionbetween its uppermost and lowermost positions, and control means adaptedto. be operated thereafter for causing said slide to move from saidintermediate position, through its lowermost position and to anintermediate position substantially the same distance from its lowermostposition as. the prior intermediate position, said adjustable meansbeing adapted to stop the upward movement of said slide when it hasreached the last said intermediate position.

6. In a mechanical punch press having a frame, a slide reciprocable inthe frame, eccentric means connected to said slide and adapted whenrotated through one complete cycle of revolution to cause said slide tomove from its uppermost position to its lowermost position and to returnto its uppermost position, a flywheel and means to rotate said flywheelat a substantially uniform. velocity: clutch means adapted to connectsaid flywheel to said eccentric means to cause rotation of saideccentric means in one direction, other clutch means adapted to connectsaid flywheel to said eccentric means to cause said flywheel to rotatesaid eccentric means in the opposite direction, brake means adapted torestrain said eccentric means against rotation, means normally engagingsaid brake means when both of said clutch means are disengaged anddisengaging said brake means when either of said clutch means isengaged, control means operative to engage one of said clutch means andto disengage said brake means to cause movement of said slide from anintermediate position through its lowermost position to substantiallythe same intermediate position at which said slide was started, theabove movement being accompanied by rotational movement of saideccentric means in one direction and control means operative tocondition said clutch means so that subsequent operation of the firstcontrol means will cause said flywheel to rotate said eccentric means inthe opposite direction to cause said slide to move from its saidintermediate position through its lowermost position and to return toits said intermediate position.

7. In a mechanical punch press having a frame, a slide reciprocable inthe frame, rotatable means connected to said slide and adapted whenrotated to cause movement of said slide through a cycle of operation, aflywheel and means to rotate said flywheel at a substantially uniformvelocity: means to rotate said rotatable means from said flywheel ineither direction and to restrain said rotatable means against rotation,said means comprising a clutch to connect said flywheel to saidrotatable means by way of a forward driving gear train, a second clutchto connect said flywheel to said rotatable means by way of reversinggear train, brake means to restrain said rotatable means againstrotation, pneumatic means adapted when in one position to causeengagement of said brake means and disengagement of both of said clutchmeans and when in another position to cause disengagement of said brakemeans and engagement of a selected one of said clutch means, and meansto select which of said clutch means is to be engaged by the last saidmeans when in the second of its alternative positions.

8. In an eccentric type punch press having a frame, a slide reciprocablein the frame, eccentric means connected to said slide and adapted whenrotated through one complete cycle of revolution to cause said slide tomove from its uppermost position to its lowermost position and to returnto its uppermost position, a flywheel and means to rotate said flywheelat a substantially uniform velocity: actuating and control means tocause said slide to move through a stroke shorter than its maximumstroke, the last said means comprising means to connect said eccentricmeans to said flywheel so as to cause rotation of said eccentric meansin one direction, means to connect said eccentric means to said flywheelto cause rotation of said eccentric means in the opposite direction,means to restrain said eccentric means against rotation, and automaticcontrol means to limit the upward movement of said slide to a p-re-setposition between its upper and lower limits, said control means adaptedto disengage said connecting means and to apply said restraining means.

9. In a mechanical punch press having a frame, a slide reciprocable inthe frame, eccentric means connected to said slide and adapted whenrotated through one complete cycle of revolution to cause saidslide tomove from its uppermost position to its lowermost position and to returnto its uppermost position, a flywheel and means to rotate said flywheelat a substantially uniform velocity: alternating operating brake andclutch means adapted alternately to restrain said eccentric meansagainst rotation and to rotate said eccentric means from said flywheel,said clutch means being adapted to rotate said eccentric means in eitherdirection, control means adapted to cause engagement of said clutchmeans and disengagement of said brake means to cause movement of saidslide, and automatically operable means adapted to disengage said clutchmeans and to apply said brake means at any predetermined point ofmovement of said eccentric means after said slide has moved through itslowermost position, and means operative thereafter to cause saidflywheel to again be connected to said eccentric means to cause rotationof eccentric means in the opposite direction, where- I

